With the development of display technology, Organic Light-Emitting Diode (OLED) display apparatuses are more and more widely used. An OLED display apparatus may comprise a plurality of pixels and a pixel driving circuit for driving the pixels, wherein each pixel comprises an OLED, and the pixel driving circuit may comprise Thin Film Transistors (TFT for short) and capacitors.
In the OLED display device, as specific factors of the TFT corresponding to various pixels, such as threshold voltages Vth, mobility, parasitic capacitances, and channel widths/lengths etc., are different, there is a problem of non-uniformity of luminance for the OLED display apparatus at the time of display.
However, there is only a circuit in the conventional technology which can detect process parameters of the TFT, but there is no circuit which can not only detect the characteristic parameters of the TFT but also can detect the characteristic parameters of the OLED.